Spatial Analysis of Composition and Species Interactions with Temporal Variation of Zooplankton Community of Shallow Tropical Lake: Thol Bird Sanctuary, India

Spatial and temporal patterns in the distribution of the zooplankton in a tropical Man-made reservoirThol Bird Sanctuary were investigated for two consecutive years from September 2007 to August 2009. The zooplankton was sampled at two different zones of Thol wetland located 23 o 15’N and 72 o 30’E near Ahmedabad city of Gujarat state, India. Sixteen species of Rotifers rich in number of individuals, density were dominant throughout the seasons in two sampling sites among the other groups. The main species were Polyarthra vulgaris, Keratella tropica, K. cochlearis and Brachionus forficula. Eleven species of Cladocera were more abundant in spring with the occurrence of Daphnia sp. and Macrothrix rosea at site 1 (feeder canal of the lake). Whereas, Diaphanosoma birgei, the most abundant Cladoceran, mainly occurred at site 2 (littoral zone of the lake). Peaks of tinted Protozoan were observed at site 1 during winter and spring. Variation in spatial distribution was noticeable, the abundance of zooplankton was significantly higher (P< 0.05) at the site 2 than the site 1 as a result of preponderance of the small Rotifers and Cladocerans particularly Bosmina longirostris. The analysis of one way ANNOVA between the sites for the first year showed the F̕ (5.84) value is greater than critical F value (4.30), whereas in the second year P’ value (0.0005) is lesser than alpha (α) value 0.05.